Do you need an airstone with a canister filter

[KerriPaul]

Have got an ecco which works fine (so long as I put a pipe cleaner up the pipes every now and then!)

I have a home made C02 injector for the plants which goes into the tank via a valve and airline and pokes into the filter inlet so the C02 goes into the filter to dissolve with the water.

The filter outlet is just a pipe end under the water to stop the C02 being lost. The danios love the currents.

However I have an airstone as I thought the fish need an air input to get oxygen but this probably causes enough ripple to remove the C02

Question is: how do the fish get enough air without an airstone as whatever the surface ripple there is only a very small air gap between the lid and the outside world and my fear is without having air from the room pumped into the tank, the fish will not get enough oxygen

 

[smithrc]

the reason your adding co2 is for the plants.... during the day... they will produce O2.

what size tank is it? what stock levels do you have?

 

[jflowers]

Its been argued many times on here, but in my view the only advantage of an air stone is adding surface agitation and that very little oxygen is absorbed from the actual bubbles. Plus adding an airstone will remove CO2 from the water (which you know), so you wont be getting much advantage by adding CO2. Can you change the position of the outflow pipe from the canister to increase the surface aggitation?

Jon

 

[KerriPaul]

Its been argued many times on here, but in my view the only advantage of an air stone is adding surface agitation and that very little oxygen is absorbed from the actual bubbles

I suspected that but what I was mainly concerned with is that because there is a lid over the top there is very little scope for the air above the tank to diffuse with the room air therefore replenishing the oxygen. My thought was that the air from an airstone would rise to the top and keep a supply of oxygenated air above the water.

Or do you only need small gaps between lid and outside world to circulate enough air?

Can you change the position of the outflow pipe from the canister to increase the surface aggitation?

Reasonably happy with the position which is just below the water so it causes a lot of ripple without breaking the surface.

 

[KerriPaul]

the reason your adding co2 is for the plants.... during the day... they will produce O2.

But at night?, plus during the winter it dosent get nearly so much light.

What size tank is it? what stock levels do you have

20 Uk Gal.

Large amount of danios (am planning a bigger tank)

 

[jflowers]

Reasonably happy with the position which is just below the water so it causes a lot of ripple without breaking the surface.

Then you have enough IMO. The small gap between the water and condensation cover should not make any difference as long as its not air tight (which it can't be).

Jon

 

[dirtydogg]

at night plants consume oxygen.

 

[yvez9]

if you add co2, you don't want surface agitation otherwise you're losing your co2

do you really need co2? also, if your fish all look happy right now, i wouldn't worry